The rotary electrical machine comprises a rotor and stator on each of which an electric coil can be produced.
This rotary electrical machine may be an alternator that makes it possible to convert a rotation movement of the rotor into an electric current. The electrical machine can also be a motor that makes it possible to convert an electric current passing through the coil of the rotor into a rotation movement of the rotor. The machine may also be reversible and therefore convert mechanical energy into electrical energy and vice versa.
A rotor conventionally comprises:                a magnetic core,        an electrical coil that comprises a winding of at least one conductive element,        a coil support comprising at least one annular transverse flange serving in particular for winding at least one conductive element.        
The coil is produced during a step of winding the conductive element, which makes it possible to form turns regularly distributed on the magnetic coil. The coil is then in the form of a horizontal and vertical juxtaposition of turns, forming radially superimposed conductive element layers. The conductive element has, in transverse section, a generally round shape.
It can also be noted that the conductive element comprises an electrically conductive part, for example a copper wire, and an electrically insulating part, for example a layer of enamel surrounding the copper wire.
However, during the use of the rotary machine, because of the vibrations and under the effect of centrifugal force, the turns of the electrically conductive element move with respect to one another and rub either on one another or against at least one flange of the coil support. Thus the enamel protecting the copper wire may be damaged. The short-circuits resulting from this cause the rotary machine to be put out of use more or less rapidly.
In addition, there exist interstices between adjacent turns of the electrically conductive elements. These interstices are filled with air. However, during the functioning of the electrical machine, the turns heat up. The air present in the interstices being a thermal insulator, discharge of the heat to the outside of the coil is not optimised. The efficiency of the machine is therefore reduced.
To avoid these drawbacks, the document FR 1560304 discloses a method of manufacturing a coil of a rotor of a rotary electrical machine. This rotor comprises teeth belonging to magnet wheels. After having formed a coil on a magnetic core by a step of winding at least one conductive element, interstices existing between adjacent turns are filled with a binder, forming an impregnation means. This binder is a better thermal conductor than air. For this purpose, a distribution head pours the binder, when the rotor is at rest, using the space that exists between the two adjacent teeth. Then the rotor turns through an angle of 120°, and the distribution head pours the binder once again. The binder is thus poured at several points distributed over the circumference of the windings. This distribution therefore takes place in several steps.
The method disclosed in this document does not make it possible to fill in a satisfactory manner all the interstices existing between the adjacent turns of the electrically conductive element.
This is because, the rotor being mounted with its magnet wheels, the distributor cannot approach the coil in an optimum manner. The result is that the pouring of the binder cannot be precise. There are thus risks that the binder may be poured onto areas of the rotor that should not normally receive it, such as the teeth or magnet wheels.
In addition, the distributor deposits the binder at isolated points on the circumference of the coil. Thus the interstices existing between the adjacent turns of the top layers of the coil are not all filled uniformly.
In addition, in a case where the density of the turns of the electrically conductive element in the winding is great, the binder cannot reach the interstices existing between the adjacent turns of the internal layers of the coil.
Finally, the method as presented in the prior art is not optimised in terms of time since the binder is poured on the coil on several occasions.